Maryland Department of Natural Resources

Maryland Geological Survey Begins New Survey of Mason-Dixon Line

January 27, 2020

The Maryland Geological Survey, a unit of the Maryland Department of Natural Resources, will lead professional surveying societies of Maryland and Pennsylvania in a new survey of monuments along the Mason-Dixon Line. This will be the first complete survey in 40 years of the line, which was marked in a 1760s survey that defined the Maryland-Pennsylvania border.

Surveyors will document and photograph the monuments to create a thorough collection of the remaining monuments with the intent of entering them into the National Registry of Historic Places. The project is slated to begin in February and continue through August 2021.

Maryland Geological Survey is working with the Commonwealth of Pennsylvania, Maryland Historical Trust, the Maryland Society of Surveyors, and the Pennsylvania Society of Land Surveyors on the effort. Fieldwork will be conducted by the two professional societies at no cost.

The department is also asking for the public’s help. People who own property within the survey zone are asked to allow access to the site — all surveyors will have identification and documentation from the Department of Natural Resources. Also the surveyors would be interested to hear and document any stories people have about the monuments.

"A plan of the west line or parallel of latitude, which is the boundary between the provinces of Maryland and Pensylvania : a plan of the boundary lines between the province of Maryland and the Three Lower Counties on Delaware with part of the parallel of latitude which is the boundary between the provinces of Maryland and Pennsylvania" - [Published Philadelphia : Robert Kennedy, 1768]
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